title: Concise synthesis of complicated polypropionates through one-pot dissymmetrical two-directional chain elongation.
abstract: Herein, a major breakthrough in a sulfur dioxide-mediated oxyallylation cascade reaction is reported that allows the preparation of complex long-chain polyketide fragments with more than ten stereogenic centers through a carefully designed desymmetrization process. An allylbissilane is combined, under the appropriate reaction conditions, with two different 1,3-dioxy-1,3-dienes permitting the construction of a 13-membered polypropionate precursor in one pot. Four stereocenters are selectively created during this process. The so-obtained pseudo-C(2)- or -C(S)-symmetric products are desymmetrized through selective deprotection and can be selectively elongated in both directions using aldol chemistry.
authors.affiliation: Laboratoire de Glycochimie et de Synthèse asymétrique, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Claudia J
authors.initials: CJ
authors.lastname: Exner
authors.forename: Maris
authors.initials: M
authors.lastname: Turks
authors.forename: Freddy
authors.initials: F
authors.lastname: Fonquerne
authors.forename: Pierre
authors.initials: P
authors.lastname: Vogel
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D015394:Molecular Structure; D011422:Propionates / Q000138:chemical synthesis* / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*; D013237:Stereoisomerism; D013458:Sulfur Dioxide / Q000737:chemistry*
chemical_list: D000475:Alkenes; D011422:Propionates; D012821:Silanes; D013458:Sulfur Dioxide